Use deterministic maps for FamInstEnv

We turn FamInstEnvs into lists in some places which
don't directly affect the ABI. That happens in
family consistency checks and when producing output
for `:info`. Unfortunately that nondeterminism
is nonlocal and it's hard to tell locally what it
affects. Furthermore the envs should be relatively
small, so it should be free to use deterministic
maps here. Testing with nofib and ./validate detected
no difference between UniqFM and UniqDFM.

GHC Trac: #4012

1 files changed, 10 insertions, 10 deletions

diff --git a/compiler/types/FamInstEnv.hs b/compiler/types/FamInstEnv.hs
index 3f07c216d1..c860dbc5e5 100644
--- a/compiler/types/FamInstEnv.hs
+++ b/compiler/types/FamInstEnv.hs
@@ -48,7 +48,7 @@ import VarSet
 import VarEnv
 import Name
 import PrelNames ( eqPrimTyConKey )
-import UniqFM
+import UniqDFM
 import Outputable
 import Maybes
 import TrieMap
@@ -361,7 +361,7 @@ These two axioms for T, one with one pattern, one with two;
 see Note [Eta reduction for data families]
 -}
 
-type FamInstEnv = UniqFM FamilyInstEnv  -- Maps a family to its instances
+type FamInstEnv = UniqDFM FamilyInstEnv  -- Maps a family to its instances
      -- See Note [FamInstEnv]
 
 type FamInstEnvs = (FamInstEnv, FamInstEnv)
@@ -381,16 +381,16 @@ emptyFamInstEnvs :: (FamInstEnv, FamInstEnv)
 emptyFamInstEnvs = (emptyFamInstEnv, emptyFamInstEnv)
 
 emptyFamInstEnv :: FamInstEnv
-emptyFamInstEnv = emptyUFM
+emptyFamInstEnv = emptyUDFM
 
 famInstEnvElts :: FamInstEnv -> [FamInst]
-famInstEnvElts fi = [elt | FamIE elts <- eltsUFM fi, elt <- elts]
+famInstEnvElts fi = [elt | FamIE elts <- eltsUDFM fi, elt <- elts]
 
 familyInstances :: (FamInstEnv, FamInstEnv) -> TyCon -> [FamInst]
 familyInstances (pkg_fie, home_fie) fam
   = get home_fie ++ get pkg_fie
   where
-    get env = case lookupUFM env fam of
+    get env = case lookupUDFM env fam of
                 Just (FamIE insts) -> insts
                 Nothing                      -> []
 
@@ -400,14 +400,14 @@ extendFamInstEnvList inst_env fis = foldl extendFamInstEnv inst_env fis
 extendFamInstEnv :: FamInstEnv -> FamInst -> FamInstEnv
 extendFamInstEnv inst_env
                  ins_item@(FamInst {fi_fam = cls_nm})
-  = addToUFM_C add inst_env cls_nm (FamIE [ins_item])
+  = addToUDFM_C add inst_env cls_nm (FamIE [ins_item])
   where
     add (FamIE items) _ = FamIE (ins_item:items)
 
 deleteFromFamInstEnv :: FamInstEnv -> FamInst -> FamInstEnv
 -- Used only for overriding in GHCi
 deleteFromFamInstEnv inst_env fam_inst@(FamInst {fi_fam = fam_nm})
- = adjustUFM adjust inst_env fam_nm
+ = adjustUDFM adjust inst_env fam_nm
  where
    adjust :: FamilyInstEnv -> FamilyInstEnv
    adjust (FamIE items)
@@ -712,7 +712,7 @@ lookupFamInstEnvByTyCon :: FamInstEnvs -> TyCon -> [FamInst]
 lookupFamInstEnvByTyCon (pkg_ie, home_ie) fam_tc
   = get pkg_ie ++ get home_ie
   where
-    get ie = case lookupUFM ie fam_tc of
+    get ie = case lookupUDFM ie fam_tc of
                Nothing          -> []
                Just (FamIE fis) -> fis
 
@@ -875,7 +875,7 @@ lookupFamInstEnvInjectivityConflicts injList (pkg_ie, home_ie)
           | otherwise = True
 
       lookup_inj_fam_conflicts ie
-          | isOpenFamilyTyCon fam, Just (FamIE insts) <- lookupUFM ie fam
+          | isOpenFamilyTyCon fam, Just (FamIE insts) <- lookupUDFM ie fam
           = map (coAxiomSingleBranch . fi_axiom) $
             filter isInjConflict insts
           | otherwise = []
@@ -915,7 +915,7 @@ lookup_fam_inst_env'          -- The worker, local to this module
     -> [FamInstMatch]
 lookup_fam_inst_env' match_fun ie fam match_tys
   | isOpenFamilyTyCon fam
-  , Just (FamIE insts) <- lookupUFM ie fam
+  , Just (FamIE insts) <- lookupUDFM ie fam
   = find insts    -- The common case
   | otherwise = []
   where